SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ad300965999419bdca773f536c09da7c129e7206dca862977ea8f4734c2f0681' 
  AND token = 'GaEyYCLBEOFebNNQpL/mwX7hA8gxNciwfoErWclDnL0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}